Process for making rubber thread



Patented Aug. 29, 1933 PROCESS Foil MAKING RUBBER THREAD Willis A. Gibbons, Montclair, N. .l., assignor to Revere Rubber Eornpany, Providence, R. 1., a' corporation of Rhode Island N Drawing. Application February 25,1932 Serial No. 595,235

12 Claims.

This invention relates to a process for making rubber thread, and more particularly to a process for manufacturing filaments, threads or hands,

hereinafter generically termed thread, from coagulable dispersions of elastic materials, such as rubber latex.

A process for manufacturing rubber thread from latex by passing a stream of latex through an orifice into a bath of coagulant'and continuously withdrawing a formed rubber thread from the coagulating bath and subsequently drying and vulcanizing, if desired, has been known for some time.

The present invention relates to a process for making rubber thread which includes passing a stream of coagulant into a body of latex and continuously Withdrawing the resulting filamentary ooagulum.

In the preferred method of carrying out the invention, a stream of coagulant is passed through a suitable nozzle into a bath of-latex to coagulate latex about the stream and form a substantially solid thread which may be continuously withdrawn from the main body of latex. As the coagulant leaves the nozzle and comes in contact with the bath of latex, a filamentary coagulum or gel is formed initially surrounding a liquid core of coagulant; then, as the thread or filament passes through the latex bath or through later stages of the process, it becomes substantially coreless. As the thread is Withdrawn from the latex bath it is coated with uncoagulated latex, hence it is desirable to thereafter harden the surface of the thread by subjecting it to a further setting or coagulating treatment. This may be done by drawing the thread from the latex and over a roll of which the surface is kept wet with coagulant or by spraying or otherwise applying 4O coagulant to the surface of the thread after it has been removed from the latex, or by passing the thread through a groove provided with an orifice in the bottom through which coagulant emerges into the groove in small quantities, or by any combinations of such steps, or by other methods within the skill of those familiar in the art. The size of the filament depends on the size of the nozzle, the rate of flow of coagulant through the nozzle, the nature of the coagulant, the rate of coagulation of the latex, the length of travel through the latex bath,and the rate of withdrawal of the filament from the bath. According to this invention, various well known latex coagulants such as aqueous solutions of acetic acid, preferably containing from -25% acetic acid, or alcohol or mixture of acetic acid and alcohol may be used as thread-forming coagulants and various other coagulants will be apparent to those skilled in the art. The coagulant liquid may be thickened to any desired consistency by the addition thereto of any suitable material which is soluble or dispersible therein, such as cellulose acetate, or various gums and'resins, natural or artificial. The surface of the formed. thread may be hardened, as described above,-by the use of solutions of di-' or tri-valent metals as well as by the coagulants indicated above.

It is, of course, obvious that the viscosity of the coagulant liquid, the method of drying the filament, the composition of the dispersion with reference to the various compounding ingredients, the rate of flow of thecoagulant through v the nozzle, the rate of withdrawal of the thread, and the length of travel through the latex bath may be varied as desired. The latex maybe vulcanized, or it may be unvulcanized with or without vulcanizing ingredients added thereto.

If a vulcanized thread is desired, it may be obtained by compounding the latex with suitable vulcanizing ingredients, forming athread therefrom, and vulcanizing the final product; or it 0. may also be formed from a vulcanized latex as suggested above, or a thread formed from unvulcanized latex Without vulcanizing ingredients may be subjected to the action of vulcanizing liquids or vapors, or to solutions containing vul- 1 canizing ingredients. The latex may be made heat sensitive by methods well known in the art and a hot coagulant streamed into such a heat sensitive latex in the manner above described.

The term"latex in the description and claims 9 is used to designate broadly coagulable dispersions of elastic materials, includingartificial dispersions of rubber or rubber-like materials as well as natural latex, which may be preserved or otherwise treated as desired, and which may be in a normal, diluted, concentrated or purified condition produced by methods well known in the art.

Various other modifications will'be apparent to persons skilled in the art and it is understood that I do not intend to limit myself to the specific improvements as described above except as indicated in the appended claims:

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. A process for making rubber thread comprising the steps of streaming a coagulant into a body of latex and forming a continuous length of coagulum, and removing the length of coagulum from the latex. no

2. A process for making rubber thread comprising the steps of forming a continuous length of coagulant by introducing a stream of coagulant into a body of latex,'removing the length of coagulum from the latex, and drying.

3. A process for making rubber thread comprising the steps of forming a continuous length of coagulum by introducing a stream of coagulant into a body of latex, removing the length of coagulum from the main body of latex, and vulcanizing.

4. A process for making rubber thread comprising passing a stream of coagulant through a nozzle into latex to coagulate said latex about said stream and thereby form a filamentary coaguluin containing a liquid core of coagulant, allowing said coagulum to remain in contact with the latex until a substantially coreless thread has been formed therefrom, and continuously withdrawing said solid thread from the latex.

5. A process for making rubber thread comprising the steps of streaming a coagulant into latex thereby forming initially a filamentary coagulum surrounding acore of coagulant, drawing the coagulum through the latex until a substantially coreless coagulum in the form of a thread is produced, and continuously withdrawing'the thread from the latex.

6. A process for making rubber thread comprising introducing 'a stream of coagulant into latex to coagulate said latex about said stream and form a thread thereby, removing the thread from the main body of latex, and drying.

7. A process for making rubber thread comprising introducing a stream of coagulant into latex to coagulate said latex about said stream and form a thread thereby, continuously removing the thread from the main body of latex, drying and vulcanizing.

8. A process for making rubber thread comprising introducing a stream of coagulant into latex to coagulate said latex about said stream and form a thread thereby, continuously removing the thread from the main body of latex, setting or coagulating the surface of the thread, and drying the thread.

9. A process for making rubber thread comprising the steps of continuously passing a stream of coagulant through a nozzle into a body of latex, drawing the formed coagulum away from the nozzle, and withdrawing the resulting filamentary coagulum from the body of latex.

10. A processfor making rubber thread comprising continuously passing a stream of coagulant through a nozzle into a body of latex, drawing the formed coagulum away from the nozzle, withdrawing the resulting filamentary coagulum from the body of the latex, and drymg. I

11. A process for making rubber thread com prising continuously passing a stream. of 00 agulant through a nozzle into a body of latex drawing the formed coagulum away from the nozzle, Withdrawing the resulting filamentary coagulum from the body of latex, drying, and vulcanizing.

12. A process for making rubber thread comprising continuously passing a stream of coagulant through a nozzle into a body of latex, drawing the formed coagulum away from the nozzle, withdrawing the resulting filamentary coagulum from the body of latex, setting or 00- agulating the surface of the thread, drying, and vulcanizing.

WILLIS A. GIBBONS. 

